This was one in a continuing line of moves that have put Kennedy's vaccine skepticism into public policy, though scientists say the vaccines are safe.

U.S. Health Secretary Robert F. Kennedy Jr. incorrectly argued mRNA vaccines are ineffective to justify the Department of Health and Human Service's recent decision to cancel $500 million in government-funded research projects to develop new vaccines using the technology.

While anti-vaxxers are thrilled, experts warn that defunding mRNA development takes away our already-proven best weapon against future pandemics.